Device for minimally invasive plastic surgery lift procedure

ABSTRACT

Described are medical devices configured for use in cosmetic surgery and methods for repositioning tissue in a patient. The medical devices include an elongate body member having a proximal end, a distal end, and a plurality of gaps defined therebetween. The body member comprises one ore more layers of a collagenous extracellular matrix (ECM) material. 
     The elongate member can include one or more tissue engaging members. In preferred embodiments, the collagenous extracellular matrix material includes one or more native or non-native bioactive components.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/774,980, filed May 6, 2010, and which claims the benefit of U.S.Provisional Patent Application Ser. No. 61/175,823 filed May 6, 2009.These applications are hereby incorporated by reference in theirentirety.

BACKGROUND

The present invention relates generally to medical devices configured tobe useful in cosmetic surgery and, in particular, to such devices foruse in a soft tissue lift procedure.

With an aging population, cosmetic surgery has become a popular choicefor many people seeking to improve the look of one or more personalfeatures. For this reason, plastic surgeons have sought to developmethods and devices to support tissue that has lost its natural tension,including tissue of the face, neck, chest, buttocks, or any other areawhere tissue can sag over time.

One of the more popular procedures involves lifting tissue of the faceand neck, which is typically referred to as a rhytidectomy. Arhytidectomy can be performed to improve sagging in the midface, deepcreases below the lower eyelids, deep creases along the nose extendingto the corner of the mouth, fat that has fallen or is displaced, loss ofmuscle tone in the lower face that may create jowls, and loose skin andexcess fatty deposits under the chin and jaw.

In a traditional rhytidectomy, an incision is made in front of the earextending up into the hairline. The incision curves around the bottom ofthe ear and then behind it, usually ending near the hairline on the backof the neck. After the skin incision is made, the skin is separated fromthe deeper tissues, and the deeper tissues can be tightened withsutures. The skin is then redraped over the lifted tissue.

Modern developments for performing a rhytidectomy involve the use of amedical implant. One such implant is the Endotine Midface™ device. Thedevice includes an enlongated strip of a bioabsorbable material with afixation platform at one end. The fixation platform is inserted into theface at a point where a lift is desired and is pulled in a backwardsdirection to lift tissue. The device is then secured to prevent theimplant from coming loose.

Soft tissue remains difficult to manipulate by virtue of its inabilityto hold tension. Moreover, devices used to assist in holding tension canbe difficult to surgically implant and, once implanted, can be extremelyuncomfortable to a patient. As well, bioabsorbable implants can absorbtoo quickly, which can result in lifted tissue reverting back to itsoriginal position. Accordingly, a need remains for alternative andimproved medical devices for use in cosmetic surgery, most notablyimproved implants for performing a rhytidectomy. The present inventionaddresses these needs.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a medical device. Themedical device includes an elongate body member having a proximal end, adistal end, and a plurality of gaps defined therebetween. The bodymember includes at least one tissue engaging member extending laterallytherefrom and comprises one or more layers of a collagenousextracellular matrix (ECM) material. The medical device also includes abase member configured to substantially prevent the body member frommoving when the tissue engaging member is engaged with tissue.

The tissue engaging members can extend laterally from the elongate bodymember. The base member can also comprise a collagenous ECM material.Alternatively, the base member can comprise a bioabsorbable polymer,such as poly(lactic-co-glycoloic) acid.

Further provided by the invention is a method for repositioning tissuein a patient. The method includes inserting a medical device into thepatient; engaging the medical device so as to reposition tissue of thepatient; and attaching the base member of the medical device to tissueof the patient.

In another aspect, the present invention provides a method forrepositioning soft tissue of a patient. The method includes forciblyrelocating a segment of soft tissue from a first position to a secondposition in such a manner as to introduce tension into the segment ofsoft tissue and into adjacent soft tissue. The segment of soft tissue isretained in the second position with a tissue engaging member thatengages soft tissue proximate to the second position. A remodelableextracellular matrix material is interposed between the segment of softtissue and soft tissue proximate to the second position. The remodelablematerial is effective to result in the ingrowth of new tissue of thepatient to fuse the segment of soft tissue to the soft tissue proximateto the second position.

Additional embodiments as well as features and advantages of theinvention will be apparent from the descriptions herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a perspective view of a medical device of the presentinvention.

FIG. 2 depicts a perspective view of a medical device of the presentinvention including a base member.

FIG. 3 depicts a perspective view of a base member that can be used tosecure a medical device to a desired location in a patient.

FIGS. 4A-4D depict perspective views of various designs for a basemember that can be used to secure a medical device to a desired locationin a patient.

FIGS. 5A-5D depict perspective views of an alternate design for a basemember that can be used to secure a medical device to a desired locationin a patient.

DETAILED DESCRIPTION

As noted above, the present invention provides a medical device useful,for example, in cosmetic surgery applications. The device includes anelongate body member having a proximal end, a distal end, and aplurality of gaps defined therebetween. At least one tissue engagingmember is included on the body member and extends laterally therefrom.One or more layers of a collagenous material, preferably a collagenousextracellular matrix (ECM) material, is associated with the body member.While not wishing to be bound by any particular theory, it is believedthat the association of a collagenous ECM material with the body memberwill allow the body member to exist in vivo for a sufficient time so asto substantially prevent the lifted tissue from reverting back to itsunlifted position. The collagenous ECM material can also encourageinfiltration of the lifted tissue to provide a more permanent result.

Body members for incorporation into the present medical devices aregenerally elongate and include a proximal end and a distal end. Suchmembers may be made from metallic or non-metallic material, or both. Thenon-metallic material can suitably be a synthetic polymeric materialincluding, for example, bioresorbable and/or non-bioresorbable plastics.Materials commonly used in body member construction include syntheticpolymeric materials such as silicone; low shape memory plastic; ashape-memory plastic or alloy, such as nitinol; and the like. The bodymember can also be constructed of a collagenous extracellular matrix(ECM) material. Preferably, the body member is constructed of abioabsorbable polymer, such as poly(lactic-co-glycolic) acid (PLGA). Inthis respect, the body member can be a rigid body member, a semi-rigidbody member, or a soft body member. As used herein, a “rigid bodymember” refers to a body member comprised of a material which isgenerally solid throughout and can resist degradation in vivo while a“soft body member” is comprised of a material such as a sponge or afoam. A “semi-rigid body member” generally refers to those materialsthat are rigid but can become less rigid after implantation into apatient e.g., resorbable materials. Semi-rigid body members arepreferably used to construct a body member for the medical devicesdescribed herein. Whichever material is chosen it will be preferred thatthe elongate member exhibit a tensile strength of about 1 pound persquare inch to about 10 pounds per square inch and, more preferably, atensile strength of about 2 pounds per square inch to about 5 pounds persquare inch.

A body member for use in the present medical devices can be any suitableshape. For example, the body member can be a cylindrical device having adiameter extending from the proximal end to the distal end. The diametercan be substantially the same throughout the length of the member or canbe different. Alternatively, the body member can be substantiallyplanar. In preferred embodiments, the body member is substantiallyplanar.

A body member as described herein can also be any suitable length. Forexample, a body member can be from about 1 inch to about 24 inches.Preferably, the body member has a length from about 3 inches to about 12inches, and more preferably from about 5 inches to about 10 inches.These length ranges are meant to serve merely as examples and, as such,are in no way limiting. In this respect, body members having a lengthsmaller than or larger than the ranges indicated above are contemplatedfor use herein.

A body member as described herein can also be any suitable width. Forexample, a body member can be from about 0.25 cm to about 2 cm. It willbe understood that the desired width of a body member will typicallydepend on its intended use. A body member used to lift facial tissuewill generally be from about 0.25 cm to about 0.75 cm, and preferably0.5 cm. Of course, the smaller the width of the body member results inthe smaller incision required to insert the device into a patient. Inthis respect, a body member having a width from about 1 mm to about 10mm is also contemplated. A body member having a width from about 2 mm toabout 4 mm is particularly preferred. A body member for use in liftingtissue of the arms, thighs, breasts, buttocks, back and abdomen, forinstance, will typically be wider, such as 0.75 cm to about 2.0 cm, andpreferably 1.0 cm.

A body member as described herein includes a plurality of gaps. Theplurality of gaps extend from the proximal end of the body membertowards the distal end. Any number of gaps can be included on the bodymember. The gaps can be preformed during preparation of the body memberor can be formed in the body member after its production. The pluralityof gaps can be included in the body member in any suitable pattern.Preferably, the plurality of gaps extend from the proximal end towardsthe distal end and are spaced evenly from one another. The plurality ofgaps can extend from the proximal end to the distal end any desiredlength and will preferably extend towards the distal end at least about10%, 20%, 30%, 40% or even at least about 50% or more of the length ofthe body member. In certain embodiments, the plurality of gaps canextend the entire length of the body member.

A body member as described herein includes at least one tissue engagingmember. The tissue engaging member can be constructed of the samematerial as the body member or can be constructed of a differentmaterial. In one embodiment, the tissue engaging member is constructedof a material that absorbs at a faster or slower rate after implantationas compared to the body member. In any case, it is preferred that thetissue engaging member(s) be formed of a bioabsorbable material, such asa bioabsorbable polymer (e.g., PLGA). In such embodiments, the tissueengaging member(s) can retain their general shape and strength for atime sufficient to allow tissue that has been repositioned to fuse atthat location.

In a preferred embodiment, the body member includes a plurality oftissue engaging members extending a certain length along the bodymember. For example, the body member can include tissue engaging membersin a generally symmetrical fashion along both sides of the body memberand extending at least about 10%, 20%, 30%, 40% or even at least about50% or more of the length of the body member from the proximal end tothe distal end. Preferably, such tissue engaging members are spacedevenly from one another. It will be generally understood by thoseskilled in the art that the tissue engaging member(s) can be positionedat any location along the length of the body member. As well, any numberof tissue engaging members can be included along the length of the bodymember. Thus, one skilled in the art can use a medical device having thedesired length and desired quantity of tissue engaging members for agiven procedure.

The tissue engaging member(s) can be any shape and, in certainembodiments, may take the form of barbs or hooks. In preferredembodiments, the tissue engaging member(s) include a rounded tip forcontacting tissue. Such adaptations may be included in the body memberin areas not associated with a collagenous material or, alternatively,can protrude from the body member and through the collagenous material.The tissue engaging members can be any suitable length and are typicallyabout 2 mm to about 10 mm. Preferably, the tissue engaging members areabout 8 mm in length. The tissue engaging member(s) can extend from thebody member in any direction.

For example, the tissue engaging member(s) can extend laterally from thebody member at an angle of about 45° towards the proximal end or about45° towards the distal end. Alternatively, the tissue engaging memberscan extend from the body member at an angle of about 180°. Tissueengaging members can extend at the same angle or different angles fromthe body member. As well, a tissue engaging member can extend from thebody member in a downwards or upwards direction and thus existing in adifferent plane than the body member. Preferably, the tissue engagingmembers will each extend laterally from the body member at an angle ofabout 45° towards the distal end.

A medical device as described herein can be secured in place with a basemember. The base member includes at least one slot adapted to receive amedical device. The base member is configured to substantially prevent amedical device from reverting back to its original position after it hasbeen engaged to lift tissue. A base member as described herein isgenerally configured for use with a medical device including an elongatebody member.

As noted herein, a collagenous ECM material can be used in the presentinvention as a medical device and/or a base member used to secure adevice to a body structure. Reconstituted or naturally-derivedcollagenous materials can be used in the present invention. Suchmaterials that are at least bioresorbable will provide advantage in thepresent invention, with materials that are bioremodelable and promotecellular invasion and ingrowth providing particular advantage.

Suitable bioremodelable materials can be provided by collagenousextracellular matrix materials (ECMs) possessing biotropic properties,including in certain forms angiogenic collagenous extracellular matrixmaterials. For example, suitable collagenous materials include ECMs suchas submucosa, renal capsule membrane, dermal collagen, dura mater,pericardium, fascia lata, serosa, peritoneum or basement membranelayers, including liver basement membrane. Suitable submucosa materialsfor these purposes include, for instance, intestinal submucosa,including small intestinal submucosa, stomach submucosa, urinary bladdersubmucosa, and uterine submucosa. As prepared, the submucosa materialand any other ECM used may optionally retain growth factors or otherbioactive components native to the source tissue. For example, thesubmucosa or other ECM may include one or more native growth factorssuch as basic fibroblast growth factor (FGF-2), transforming growthfactor beta (TGF-beta), epidermal growth factor (EGF), and/or plateletderived growth factor (PDGF). As well, submucosa or other ECM used inthe invention may include other biological materials such as heparin,heparin sulfate, hyaluronic acid, fibronectin and the like. Thus,generally speaking, the submucosa or other ECM material may include anative bioactive component that induces, directly or indirectly, acellular response such as a change in cell morphology, proliferation,growth, protein or gene expression.

Submucosa or other ECM materials of the present invention can be derivedfrom any suitable organ or other tissue source, usually sourcescontaining connective tissues. The ECM materials processed for use inthe invention will typically include abundant collagen, most commonlybeing constituted at least about 80% by weight collagen on a dry weightbasis. Such naturally-derived ECM materials will for the most partinclude collagen fibers that are non-randomly oriented, for instanceoccurring as generally uniaxial or multi-axial but regularly orientedfibers. When processed to retain native bioactive factors, the ECMmaterial can retain these factors interspersed as solids between, uponand/or within the collagen fibers. Particularly desirablenaturally-derived ECM materials for use in the invention will includesignificant amounts of such interspersed, non-collagenous solids thatare readily ascertainable under light microscopic examination. Suchnon-collagenous solids can constitute a significant percentage of thedry weight of the ECM material in certain inventive embodiments, forexample at least about 1%, at least about 3%, and at least about 5% byweight in various embodiments of the invention.

The submucosa or other ECM material used in the present invention mayalso exhibit an angiogenic character and thus be effective to induceangiogenesis in a host engrafted with a device including the material.In this regard, angiogenesis is the process through which the body makesnew blood vessels to generate increased blood supply to tissues. Thus,angiogenic materials, when contacted with host tissues, promote orencourage the formation of new blood vessels. Methods for measuring invivo angiogenesis in response to biomaterial implantation have recentlybeen developed. For example, one such method uses a subcutaneous implantmodel to determine the angiogenic character of a material. See, C.Heeschen et al., Nature Medicine 7 (2001), No. 7, 833-839. When combinedwith a fluorescence microangiography technique, this model can provideboth quantitative and qualitative measures of angiogenesis intobiomaterials. C. Johnson et al., Circulation Research 94 (2004), No. 2,262-268.

Further, in addition or as an alternative to the inclusion of nativebioactive components, non-native bioactive components such as thosesynthetically produced by recombinant technology or other methods, maybe incorporated into the submucosa or other ECM tissue. These non-nativebioactive components may be naturally-derived or recombinantly producedproteins that correspond to those natively occurring in the ECM tissue,but perhaps of a different species (e.g. human proteins applied tocollagenous ECMs from other animals, such as pigs). The non-nativebioactive components may also be drug substances. Illustrative drugsubstances that may be incorporated into and/or onto the ECM materialsused in the invention include, for example, antibiotics,thrombus-promoting substances such as blood clotting factors, e.g.thrombin, fibrinogen, and the like. These substances may be applied tothe ECM material as a premanufactured step, immediately prior to theprocedure (e.g. by soaking the material in a solution containing asuitable antibiotic such as cefazolin), or during or after engraftmentof the material in the patient.

A non-native bioactive component can be applied to a collagenousextracellular matrix material by any suitable means. Suitable meansinclude, for example, spraying, impregnating, dipping, etc. Thenon-native bioactive agent can be applied to the collagenousextracellular matrix material either before or after the material isaffixed to an elongate member. Similarly, if other chemical orbiological components are included in the collagenous extracellularmatrix material, the non-native bioactive component can be appliedeither before, in conjunction with, or after these other components.

Submucosa or other ECM tissue used in the invention is preferably highlypurified, for example, as described in U.S. Pat. No. 6,206,931 to Cooket al. Thus, preferred ECM material will exhibit an endotoxin level ofless than about 12 endotoxin units (EU) per gram, more preferably lessthan about 5 EU per gram, and most preferably less than about 1 EU pergram. As additional preferences, the submucosa or other ECM material mayhave a bioburden of less than about 1 colony forming units (CFU) pergram, more preferably less than about 0.5 CFU per gram. Fungus levelsare desirably similarly low, for example less than about 1 CFU per gram,more preferably less than about 0.5 CFU per gram. Nucleic acid levelsare preferably less than about 5 μg/mg, more preferably less than about2 μg/mg, and virus levels are preferably less than about 50 plaqueforming units (PFU) per gram, more preferably less than about 5 PFU pergram. These and additional properties of submucosa or other ECM tissuetaught in U.S. Pat. No. 6,206,931 may be characteristic of the submucosatissue used in the present invention.

In additional embodiments, medical devices of the invention can includeECM's or other collagenous materials that have been subjected toprocesses that expand the materials.

In certain forms, such expanded materials can be formed by thecontrolled contact of an ECM material with one or more alkalinesubstances until the material expands, and the isolation of the expandedmaterial. Illustratively, the contacting can be sufficient to expand theECM material to at least 120% of (i.e. 1.2 times) its original bulkvolume, or in some forms to at least about two times its originalvolume. Thereafter, the expanded material can optionally be isolatedfrom the alkaline medium, e.g. by neutralization and/or rinsing. Thecollected, expanded material can be used in any suitable manner in thepreparation of a medical device. Illustratively, the expanded materialcan be enriched with bioactive components, formed into one or morelayers, dried, and then associated with a body member.

Expanded collagenous or ECM materials can be formed by the controlledcontact of a collagenous or ECM material with an aqueous solution orother medium containing sodium hydroxide. Alkaline treatment of thematerial can cause changes in the physical structure of the materialthat in turn cause it to expand. Such changes may include denaturationof the collagen in the material. In certain embodiments, it is preferredto expand the material to at least about three, at least about four, atleast about 5, or at least about 6 or even more times its original bulkvolume. The magnitude of the expansion is related to several factors,including for instance the concentration or pH of the alkaline medium,exposure time, and temperature used in the treatment of the material tobe expanded. ECM materials that can be processed to make expandedmaterials can include any of those disclosed herein or other suitableECM's. Typical such ECM materials will include a network of collagenfibrils having naturally-occurring intramolecular cross links andnaturally-occurring intermolecular cross links. Upon expansionprocessing as described herein, the naturally-occurring intramolecularcross links and naturally-occurring intermolecular cross links can beretained in the processed collagenous matrix material sufficiently tomaintain the collagenous matrix material as an intact collagenous sheetmaterial; however, collagen fibrils in the collagenous sheet materialcan be denatured, and the collagenous sheet material can have analkaline-processed thickness that is greater than the thickness of thestarting material, for example at least 120% of the original thickness,or at least twice the original thickness.

Illustratively, the concentration of the alkaline substance fortreatment of the remodelable material can be in the range of about 0.5to about 2 M, with a concentration of about 1 M being more preferable.Additionally, the pH of the alkaline substance can in certainembodiments range from about 8 to about 14. In preferred aspects, thealkaline substance will have a pH of from about 10 to about 14, and mostpreferably of from about 12 to about 14.

In addition to concentration and pH, other factors such as temperatureand exposure time will contribute to the extent of expansion, asdiscussed above. In this respect, in certain variants, the exposure ofthe collagenous material to the alkaline substance is performed at atemperature of about 4 to about 45° C. In preferred embodiments, theexposure is performed at a temperature of about 25 to about 40° C., with37° C. being most preferred. Moreover, the exposure time can range fromat least about one minute up to about 5 hours or more. In someembodiments, the exposure time is about 1 to about 2 hours. In aparticularly preferred embodiment, the collagenous material is exposedto a 1 M solution of NaOH having a pH of 14 at a temperature of about37° C. for about 1.5 to 2 hours. Such treatment results in collagendenaturation and a substantial expansion of the remodelable material.Denaturation of the collagen matrix of the material can be observed as achange in the collagen packing characteristics of the material, forexample a substantial disruption of a tightly bound collagenous networkof the starting material. A non-expanded ECM or other collagenousmaterial can have a tightly bound collagenous network presenting asubstantially uniform, continuous surface when viewed by the naked eyeor under moderate magnification, e.g. 100× magnification. Conversely, anexpanded collagenous material can have a surface that is quitedifferent, in that the surface is not continuous but rather presentscollagen strands or bundles in many regions that are separated bysubstantial gaps in material between the strands or bundles when viewedunder the same magnification, e.g. about 100×. Consequently, an expandedcollagenous material typically appears more porous than a correspondingnon-expanded collagenous material. Moreover, in many instances, theexpanded collagenous material can be demonstrated as having increasedporosity, e.g. by measuring for an increased permeability to water orother fluid passage as compared to the non-treated starting material.

After such alkaline treatments, the material can be isolated from thealkaline medium and processed for further use. Illustratively, thecollected material can be neutralized and/or rinsed with water to removethe alkalinity from the material, prior to further processing of thematerial into one or more layers.

A starting ECM material (i.e., prior to treatment with the alkalinesubstance) can optionally include a variety of bioactive or othernon-collagenous components including, for example, growth factors,glycoproteins, glycosaminoglycans, proteoglycans, nucleic acids, andlipids. Treating the material with an alkaline substance may reduce thequantity of one, some or all of such non-collagenous componentscontained within the material. In certain embodiments, controlledtreatment of the remodelable material with an alkaline substance will besufficient to create a remodelable collagenous material which issubstantially devoid of nucleic acids and lipids, and potentially alsoof growth factors, glycoproteins, glycosaminoglycans, and proteoglycans.

In certain embodiments, one or more bioactive components, exogenous orendogenous, for example, similar to those removed from an expandedmaterial during alkaline processing, can be returned to the material.For example, an expanded material can include a collagenous materialwhich has been depleted of nucleic acids and lipids, but which has beenreplenished with growth factors, glycoproteins, glycosaminoglycans,and/or proteoglycans. These bioactive components can be returned to thematerial by any suitable method. For instance, in certain forms a tissueextract, such as is discussed in U.S. Pat. No. 6,375,989, containingthese components can be prepared and applied to an expanded collagenousmaterial. In one embodiment, the expanded collagenous material can beincubated in a tissue extract for a sufficient time to allow bioactivecomponents contained therein to associate with the expanded collagenousmaterial. The tissue extract may, for example, be obtained fromnon-expanded collagenous tissue of the same type used to prepare theexpanded material. Other means for returning or introducing bioactivecomponents to an expanded remodelable collagenous material includespraying, impregnating, dipping, etc. as known in the art. By way ofexample, an expanded collagenous material may be modified by theaddition of one or more growth factors such as basic fibroblast growthfactor (FGF-2), transforming growth factor beta (TGF beta), epidermalgrowth factor (EGF), platelet derived growth factor (PDGF), and/orcartilage derived growth factor (CDGF). As well, other biologicalcomponents may be added to an expanded collagenous material, such asheparin, heparin sulfate, hyaluronic acid, fibronectin and the like.Thus, generally speaking, an expanded collagenous material may include abioactive component that induces, directly or indirectly, a cellularresponse such as a change in cell morphology, proliferation, growth,protein or gene expression similar to a non-expanded collagenousmaterial.

In certain instances, an elongate member as described herein can beassociated with an extracellular matrix material. For example, anelongate body member can be associated with a single layer or multiplelayers of material. Thus, in certain embodiments, a single isolatedlayer of ECM material or a multilaminate ECM construct can be used.Illustrative multilaminate ECM constructs for use in the invention may,for example, have from two to about ten isolated ECM layers laminatedtogether.

Multilaminate ECM constructs for use in the invention can be prepared inany suitable fashion. In this regard, a variety of techniques forlaminating ECM layers together can be used. These include, for instance,dehydrothermal bonding under heated, non-heated or lyophilizationconditions, using adhesives, glues or other bonding agents, crosslinkingwith chemical agents or radiation (including UV radiation), or anycombination of these with each other or other suitable methods. Foradditional information as to multilaminate ECM constructs that can beused in the invention, and methods for their preparation, reference maybe made for example to U.S. Pat. Nos. 5,711,969, 5,755,791, 5,855,619,5,955,110, 5,968,096, and to U.S. Patent Publication No. 20050049638.

Medical devices as described herein can include a body member associatedwith a full or partial covering of a collagenous material, preferably acollagenous ECM material. In this respect, at least about 20% to about100% of a body member can be associated with a collagenous material.Preferably, at least about 50%, at least about 60%, at least about 70%,at least about 80%, at least about 90%, or even 100% of a body membercan be associated with a collagenous material. The collagenous ECMmaterial can be associated with a body member in any suitable fashion.For example, at least one layer of collagenous ECM material cansubstantially cover the body member. In another embodiment, at least onelayer of a collagenous ECM material can be included between consecutivetissue engaging members. In still another embodiment, at least one layerof a collagenous ECM material can be woven through consecutive gaps inthe body member. In some embodiments, the collagenous material isassociated in a specific manner with the body member. For example, thecollagenous material may be contoured snugly around or completely embedelements of the body member to assist in maintaining the attachment ofthe collagenous material to the body member. This may avoid, reduce, orsimplify the need for other mechanical attachments, such as sutures, tohold the collagenous material to the body member. It may also in someforms provide a specific, relatively fixed association of thecollagenous material with the body member or elements thereof.Combinations of these types of associations are also contemplated.

In one embodiment of the invention, the collagenous material isassociated with the body member by pressing or otherwise forcing thecollagenous material against surfaces of the body member while thecollagenous material is in a relatively conformable state, and thenconverting the collagenous material to a less conformable state. In thismanner, the collagenous material while conformable can locally contourto elements of the body member, e.g. elongate portions, and whenconverted to its relatively less conformable state will maintain thatcontour to the elements of the body member. As a result, the attachmentof the collagenous material to the body member will be facilitated.Further, the collagenous material may have at least some shape memoryproperties such that if converted back to a conformable state, acontoured relation between the elements of the body member and thecollagenous material will still exist.

In preferred aspects of the invention, the collagenous material will behydratable, and will be relatively more conformable when hydrated thanwhen dried. In this fashion, the collagenous material while in ahydrated state can be forced against a body member sufficiently tolocally contour the collagenous material to elements of the body member,and then dried while maintaining that force to achieve an attachment ofthe collagenous material to the body member. Advantageously, a vacuumpressing operation can be utilized to both force the collagenousmaterial against the elongate member and to dry the entire construct.Lyophilization may also be utilized for this purpose.

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and modifications in theillustrated devices, and further applications of the principles of theinvention as illustrated therein are herein contemplated as wouldnormally occur to one skilled in the art to which the invention relatesare included.

Referring now to the drawings, FIG. 1 illustrates a medical device 10 asdescribed herein. As shown, device 10 includes an elongate body member11 including a proximal end 12, a distal end 13, and a plurality of gaps14. The plurality of gaps 14 are spaced along the length of the bodymember 11 from proximal end 12 towards distal end 13 and extend towardsdistal end 13 about half of the length of elongate body member 11.Medical device 10 also includes a plurality of tissue engaging members15. Tissue engaging members 15 are located on both sides of the bodymember 11 in a generally symmetrical fashion and are spaced evenly fromone another. Similar to the plurality of gaps 14, tissue engagingmembers 15 extend from proximal end 12 towards distal end 13 about halfof the length of the body member 11. In this manner, the plurality ofgaps 14 and tissue engaging members 15 extend from proximal end 12towards distal end 13 about the same distance. Medical device 10 furtherincludes notches 16, which can be used to assist the surgeon inmanipulating device 10 through tissue. Notches 16 can also assist inretaining device 10 in a desired location once tissue has been lifted.

Referring now to FIG. 2, shown is a medical device 20 including anelongate body member 21 having a proximal end 22, a distal end 23, and aplurality of gaps 24. The plurality of gaps 24 are spaced along thelength of the body member 21 between proximal end 22 and distal end 23and extend towards distal end 23 about 75% of the length of elongatebody member 21. Medical device 20 also includes a plurality of tissueengaging members 25. Tissue engaging members 25 are located on bothsides of the body member 21 in a generally symmetrical fashion and arespaced evenly from one another. Similar to the plurality of gaps 24,tissue engaging members 25 extend from proximal end 22 towards distalend 23 about 75% of the length of the body member 21. In this manner,the plurality of gaps 24 and tissue engaging members 25 extend fromproximal end 22 towards distal end 23 about the same distance. Medicaldevice 20 also includes a base member 26 associated with the distal end23 of body member 21. Base member 26 includes attachment holes 27 forsecuring the base member 26 to a body structure. Base member 26 can beformed as part of body member 21 or can be formed separately and laterattached to distal end 23 of body member 21. Attachment can involve theuse of sutures, staples, and the like, as well as the use of a medicaladhesive as generally known in the art, or both.

Turning now to a discussion of a base member, such a base member can beconstructed of any suitable material. In preferred embodiments, the basemember will be constructed of the same material as the elongate bodymember, such as a bioabsorbable material or a collagenous extracellularmatrix material.

With reference now to FIG. 3, shown is a base member 36 for use insecuring an elongate body member to a tissue or boney structure locatedon or within a patient. Base member 36 is generally square in shape andincludes two slots 38 which are generally adapted for an elongate memberto pass through. In effect, base member 36 can act like a belt bucklewhereby an elongate member can be pulled through slots 38 in a directedD to lift tissue a desired amount.

A base member as used herein is generally configured such that a medicaldevice can be substantially prevented from moving in a forward directionafter being moved in a backwards direction D. To accomplish this, a basemember, such as base member 36, can include one or more slots thatinclude adaptations to rachet with adaptations included on a medicaldevice; thereby preventing the medical device from moving in a backwardsdirection. In other embodiments, a base member can include a pingenerally sized and shaped to receive a gap on a medical device. Thus,once the medical device has been pulled through a slot in the basemember a desired amount, the closest gap on the device can be placedover the pin so as to prevent the medical device from moving in aforward direction. The pin can be constructed as part of the base memberor can be prepared separately and subsequently attached to the basemember. Such configurations can also be used together. For example, abase member having one or more slots adapted to rachet with a medicaldevice can also include a pin generally sized and shaped to receive agap on the medical device. Other means for preventing the movement of amedical device in a backwards direction would be known to one skilled inthe art.

Once the tissue has been lifted, the base member 36 can be secured to atissue or boney structure through attachment holes 37. Any number ofattachment holes 37 can be included on a base member. Preferably, basemember 36 is secured to tissue or bone with the use of sutures, staples,and/or screws as generally known in the art. Typically, when securingthe base member to tissue, the use of sutures will be preferred, andwhen the base member is secured to bone, the use of one or more screwswill be used.

In one embodiment, the device disclosed above can be used to repositionsoft tissue of a patient. The method includes forcibly relocating asegment of soft tissue from a first position to a second position insuch a manner as to introduce tension into the segment of soft tissueand into adjacent soft tissue. The segment of soft tissue is retained inthe second position with a tissue engaging member that engages softtissue proximate to the second position. A remodelable extracellularmaterial is interposed between the segment of soft tissue and softtissue proximate to the second position. The remodelable material iseffective to result in the ingrowth of new tissue of the patient to fusethe segment of soft tissue to the soft tissue proximate to the secondposition. The segment of soft tissue can include any type soft tissueand can include combinations of soft tissue. For example, the segmentcan include dermal tissue, fatty tissue, or any other soft tissue inneed of repositioning. Typically, the soft tissue will be tissue locatedin the midface area (e.g., cheek area).

With respect to FIGS. 4A-4D, shown are various alternativeconfigurations for a base member suitable for securing a medical deviceto a body structure as described herein. FIGS. 4A and 4D illustrate abase member 46 and 76, respectively, that are substantially similar tothe base member depicted in FIG. 3 with the exception of havingdifferently shaped slots 48 and 78, respectively. FIGS. 4B and 4Cillustrate a base member 56 and 66, respectively; having a generallytrapezoidal shape and also having differently shaped slots 58 and 68,respectively. It will be understood that base member 46, 56, 66 and 76each include slots which are generally shaped to receive an elongatemember. Thus, a base member can be configured to match the shape of aparticular elongate member. In certain embodiments, a base member canalso include an extension, such as extension 69, for further securingthe base member to a body structure. Any number of extensions can beincluded on a base member. A variety of other shapes and sizes for abase member can be utilized in the present invention. Base member 46,56, 66 and 76 thus serve merely as examples and are in no way limiting.

With reference now to FIGS. 5A-5D, shown is an alternate embodiment fora base member. Base member 80 includes an inner portion 81 and an outerportion 82. A front slot 88 a is formed through outer portion 82 andextends through inner portion 81 to create a back slot 88 b. In thismanner, a space is formed extending from front slot 88 a through backslot 88 b, and this space is generally sized and shaped to receive amedical device as described herein. The base member 80 functions byinserting the distal end of a medical device into front slot 88 a suchthat it passes through arms 84 of the inner portion 81. The distal endof the medical device then exits through back slot 88 b, and the surgeoncan pull or otherwise direct the medical device in a backwards direction(i.e., away from the tissue to be lifted) to lift tissue a desiredamount. The medical device is prevented from moving in a forwarddirection (i.e., towards the tissue to be lifted) by notches 86 of arms84. Notches 86 are configured to rachet with adaptations located on amedical device such that the medical device can only move towards slot88 b. Arms 84 are thus initially not spaced far enough apart for amedical device having adaptations to pass through. However, as a medicaldevice is forced through front slot 88 a towards back slot 88 b, thedistance between arms 84 can be caused to increase by adaptations on themedical device forcing arms 84 towards outer portion 82; therebyallowing the medical device to pass through. As one set of adaptationspasses by notches 86, arms 84 automatically revert back to a widthwhereby the medical device cannot pass. Thus, one set of adaptationsremains on the back side of notches 86 while another set of adaptationsis present on the front side of notches 86. As such, a medical devicebecomes temporarily locked in place until another set of adaptations isforced through notches 86 towards back slot 88 b. If desired, a meansfor releasing the arms 84 of inner portion 81 can be included on thebase member. This can be included in the event a medical device isengaged to lift tissue too much, and the surgeon needs to release arms84 such that a medical device can be moved back through front slot 88 aa desired amount. Such a means would force arms 84 outwards toward outerportion 82 such that the width between arms 84 is increased to allow themedical device containing adaptations to pass through notches 86. Oncethe medical device has been moved through front slot 88 a, the surgeoncan disengage the means for releasing arms 84; thereby locking themedical device in place with one set of adaptations on the back side ofnotches 86 and another set of adaptations on the front side of notches86.

As shown in FIGS. 5A-5D, base member 80 is constructed of two portions.Outer portion 82 includes extensions 85, which are generally sized andshaped to receive holes 83 located on inner portion 81. Outer portion 82also includes attachment holes 87, which are generally adapted to assistin securing the base member to a body structure. This can beaccomplished with the use of staples, sutures, and the like as discussedpreviously. In practice, outer portion 82 can be secured to a bodystructure through holes 87. Inner portion 81 can then be placed overouter portion 82 by placing holes 83 of inner portion 81 over extension85 of outer portion 82. Alternatively, inner portion 81 can beassociated with outer portion 82 prior to securing outer portion 82 to abody structure. The association of inner portion 81 to outer portion 82can be temporary or can be permanent. In one embodiment, inner portion81 can remain associated with outer portion 82 until a medical devicehas been implanted for a period of time sufficient for the medicaldevice to become infiltrated with tissue. At this point, the medicaldevice is secured in place such that inner portion 81 and/or outerportion 82 can be removed.

A base member can include any number of slots. As shown in FIGS. 3 and4A-4D, base member can include two slots. In other embodiments, it iscontemplated for a base member to include a single slot, three slots,four slots, five slots, or even six or more slots. Preferably, a basemember will include two slots so as to preserve the “belt-buckle” effectof engaging a medical device received therein to lift tissue a desiredamount. The one or more slots can be formed as part of the base memberor can be cut or otherwise created in the base member after the basemember is formed.

Devices of the invention, such as devices 10 and 20, are desirablyadapted for insertion within the head and neck (e.g., facial structures,such as eyebrows, jowls, laugh lines, neck and midface), but can be usedto lift tissue located at any part of the body or mammal, preferably ahuman. For example, a medical device as described herein can be used forcosmetic lift procedures in the arms, thighs, breasts, buttocks, backand abdomen.

It is contemplated for any number of surfaces and/or structurescontained within the patient, including muscle, fat, skin and/or fascia,to be lifted by a medical device. If more than one surface and/orstructure requires lifting, a medical device can be used to lift eachsurface and/or structure and can be implanted either individually ortogether. In preferred embodiments, if more than one surface and/orstructure is in need of lifting, each structure will be treated at thesame time so as to allow for better results, particularly inpost-surgical applications where there is a high risk of tissuecollapse. In one embodiment, one device can be implanted in a deep fatlayer while a second medical device can be implanted superficially. Inany case, the medical devices described herein are generally adapted tolift soft tissue.

In order to deliver the medical device to a patient, an introducer canbe implemented. An introducer can be a generally rigid material having alumen. The lumen will be of a shape such that the medical device can bereceived therein but will not be of a shape that promotes the twistingor turning of the medical device while it is in the lumen. In this way,the lumen of the introducer will typically be substantially the sameshape as the medical device but will be sized slightly larger to allow amedical device to be received therein. Thus, the lumen can be flatand/or can have a ellipse cross-section depending on the shape of themedical device. The introducer can be constructed of any suitable rigidor semi-rigid material, such as a smooth plastic material or stainlesssteel. Preferably, the introducer will be constructed so as to minimizetissue damage during implantation of the medical device. In thisrespect, the proximal end of the introducer will preferably be roundedor otherwise shaped to reduce damage to surrounding tissue. Theintroducer can include one or more perforations to allow for hydrationand/or sterilization. Moreover, the medical device can be packaged andsterilized within the introducer such that the end user does not have toload the introducer with the medical device prior to use.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention. Ofcourse, variations of those preferred embodiments will become apparentto those of ordinary skill in the art upon reading the foregoingdescription. The inventors expect skilled artisans to employ suchvariations as appropriate, and the inventors intend for the invention tobe practiced otherwise than as specifically described herein.Accordingly, this invention includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by theinvention unless otherwise indicated herein or otherwise clearlycontradicted by context. In addition, all publications cited herein areindicative of the abilities of those of ordinary skill in the art andare hereby incorporated by reference in their entirety as ifindividually incorporated by reference and fully set forth.

What is claimed is:
 1. A medical device, said device comprising: anelongate body member having a proximal end, a distal end, and aplurality of gaps defined therebetween; said elongate body membercomprising one or more layers of a collagenous extracellular matrix(ECM) material and including at least one tissue engaging memberextending therefrom; said at least one tissue engaging member arrangedto pull tissue when said elongate body member is moved from a firstposition to a second position within the body of a patient; and a basemember associated with the distal end of said elongate body member andconfigured to substantially prevent said elongate body member frommoving from said second position to said first position when said tissueengaging member is engaged with tissue.
 2. The medical device of claim1, wherein said at least one tissue engaging member extends laterallyfrom said elongate body member.
 3. The medical device of claim 1,wherein said base member is comprised of a collagenous ECM material. 4.The medical device of claim 1, wherein said base member is comprised ofa bioabsorbable polymer.
 5. The medical device of claim 4, wherein saidbase member is poly(lactic-co-glycolic) acid.
 6. The medical device ofclaim 1, wherein said base member has a maximum outer cross-sectionaldimension greater than that of the elongate body member.
 7. The medicaldevice of claim 1, wherein said device comprises at least two layers ofa collagenous ECM material, wherein the layers are associated with oneanother to form a laminate of collagenous ECM material.
 8. The medicaldevice of claim 7, wherein said laminate of collagenous ECM material islyophilized.
 9. The medical device of claim 1, wherein said at least onetissue engaging member includes a rounded tip for contacting tissue. 10.The medical device of claim 1, wherein said at least one tissue engagingmember is constructed of a different material than the material used toconstruct the body member.
 11. The medical device of claim 1, whereinthe material used to construct the at least one tissue engaging memberabsorbs at a faster rate as compared to the material used to constructthe body member.
 12. The medical device of claim 1, wherein said medicaldevice has a tensile strength of at about 2 pounds per square inch toabout 5 pounds per square inch.
 13. The medical device of claim 1,wherein said collagenous ECM material comprises submucosa.
 14. Themedical device of claim 13, wherein said submucosa is small intestinalsubmucosa (SIS).
 15. The medical device of claim 1, wherein said basemember defines a slot adapted to receive said elongate body member. 16.The medical device of claim 15, wherein said elongate body member iswoven through slots of said base member.
 17. The medical device of claim1, wherein said base member is formed as part of said elongate bodymember.
 18. A method for repositioning tissue in a patient, comprising:inserting the medical device of claim 1 into the patient; engaging themedical device so as to reposition tissue of a patient; and attachingthe base member of said medical device to tissue of said patient.